Early next week, on April 4, the deal made between the European Union and Turkey to stem the flood of refugees into the EU goes into effect. It will promptly blow up in everybody's face, for three reasons.

First problem: the EU won't be able to "process" the arriving migrants as fast as new ones arrive. Migrants are arriving on the Greek islands of Chios and Lesbos at the rate of almost 2,000 per day, and as the weather improves even larger numbers will attempt the short sea crossing from Turkey.

Up to now the migrants have quickly been moved on to the mainland of Greece, but the Turkish-EU deal means that new arrivals will now pile up on the islands in detention camps while awaiting a decision on their asylum claims. Living conditions will become intolerable and there will be protests, some of them violent.